Rotary engine.



PATENTED JUNE' 28, 1904.

H. T. DUNN. ROTARY ENGINE.

1903.- BBNBWED DB0. 9. 190s.

APPLICATION FILED MAR. 12

4 SHEETS-SHEET 2.

N0 MODEL.

nue/Moz mi Nonms Pneus co., pHoro-nwo.. wAsumm'on. l:4 c.

PATJEINTI'zID4 JUNE 28, 1904.

H. T. DUNN. ROTARY VENGINE.

APPLIUATION FILED um. 12, 190s. RnNEwnn no. s, 190s.

4 BHEETSf-SHEET 3.

N0 MODEL.

crans co., PHOTuuTHc.. wAsHl 'PATENTED' JUNE 28, '19()4.

No. 763.865.V

' H. T. DUNN. ROTARY ENGINE. APPLIOATION FILED MAB. 12, 1903.- BENEWED DEO. 9. 1903.

4 SHEETS-SHEET 4.

N0 MODEL.

Wijnand UNITED' STATES Patented June 28, 1904.

`PATENT OFFICE.

HGH T. DUNN, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO BENJAMIN A. JACKSON, OF NEW YORK, N. Y.

ROTARY ENGINE.

SPECIFICATION forming par'. o'f Letters ramene No. 763,865, dated June 2s, 1904. Application tiled March 12, i903.r Renewed December 9, 1903. Serial No. 184,487. (No model.)

To (k1/ZZ whom t may concern:

Be it known that I, HUGH T.'DUNN, a citizen of the .United States, and a resident of New York, in the county of New York and State of New York, have invented a new and useful Improvement in Rotary Engines, of which the following isa specification.

My invention relates to an improvement in rotary engines andA in the compounding of such engines, the objects being to obtain a greater amount of power from the energy supplied to the engines, or, in other words, to cause the motive energy supplied to the enginesto perform a-'greater amount of work and entirely expend its energy in driving the shaft, thus economizing the motive power. I also contemplate the provision of a more simple and practical engine as well as one equipped with new and useful features which effectually prevent the leakage of the motive power.

To this end my invention comprises an improved construction of shaft-driving means for rotary engines It further comprises an improved method of connecting a plurality of motors or engines with one another and exhausting into each other in sequence.

It also comprises an improved abutment and method of operating the same.

It further consists in certain improvements in the pistons of the motors as well as animproved means for supplying the motive power thereto. y

' My invention further consists in certain other novel details of construction and combinations of parts, such as will be more fully described hereinafter and particularly pointed shaft, showing the manner of securing the eccentrics thereon; .and Fig. 6 is an enlarged detail viewof the sliding abutment-plate 30 partially broken away.

I have shown a series of motors l, 2, and 3, each consisting of a tubular cylinder-band 1L, provided at each end with a head 5 5. The cylinder-bands are provided at each end with a ange .6 6, the heads being suitably secured to the iianges by means of bolts, rivets, or other means. In compounding the motors each engine is placed in juxtaposition to its neighbor and one head 5 is interposed between the adjacent ends of the cylinder-bands, bolts passing through the flanges 6 6 on the adjacent ends of the cylinder-bands and through the intermediate head, thus connecting the series of engines and forming practically one motor. In this manner a very compact device can be provided which occupies a minimum of space. The joints between the cylinder bands and heads are suitably packed to prevent the leakage of the motive power. Each engine is suitably supported upon a base 7 7, the second or low-pressure engine containing about one-third more area than does the first or high-pressure engine, and the third engine posesses a still greater area in order that the same amount of impulse may be given ythe shaft in the second and third engines as in the first.

In the illustration I have shown three engines compounded; but it is evident that either a smaller or larger number might be compounded without departing from the spirit or scope of my invention, the number generally corresponding to and depending upon the amount of motive power being used.

Each cylinder-band 4 is of the general con` means of a cap-plate 11, removably secured to the cylinder band and to the heads by means of bolts or other suitable means. The heads are each provided with an angular connecting-fiange or reinforcing-strip 5, which is secured thereto and to the cap-plate in the manner shown, whereby to prevent leakage of motive power. In cases where one head is inserted between two cylinder-bands each head would be provided with two flanges, one on each side.

The heads 5 5 are of similar conformation as are the cylinder bands in cross -sectionw that is to say, approximately fan or paddle shaped-and are provided centrally of their cylindrical body portions with apertures 12, which on the outer heads are provided with suitably-packed stuffing-boxes 13 13, having suitable antifriction or roller bearings located therein. A main line or drive-shaft 14 passes centrally through the motor or the series of motors and out of the stuiiing or journal boxes 13 13, the packing therein preventing the escape of lubricant and motive power. This shaft is designed to drive any suitable mechanism and intended to b e engaged by the bearings located in the stufiing or journal boxes. This shaft is cylindrical in cross-section at the points where it passes through the heads; but intermediate the heads and interiorly of the piston-chamber the shaft is provided with a flattened seat or chorded face 15. The shaft interiorly of the piston-chamber is also lprovided with a plurality of oppositely-disposed parallel grooves 16 16. Eccentrics 17 17, each having a recessed portion 18 18, are provided, the shaft 14 being received in the recessed portions or open slots, the walls of which slots are received in the grooves 16 16, the latter serving to guide the eccentrics. Seated upon the chorded face or seat 15 of the shaft are wedges 19 19, their inclined faces engaging the rear inclined walls 20 2O of the slots 13 18. The smaller adjacent ends of the wedges 19 19 may be connected with each other by means of an open spring serving to draw the wedges toward each other.

Adjustable ball-races 21 21 arefcarried by the shaft, the balls 22 22 adapted to have rolling contactr with the heads 5 5 of the engines, the ball-races being held in their adjusted positions in any suitable manner. Connected with or secured to the larger endA ofv each of the wedge members 19 19 by any suitable means, as shown, are plates 23 23, and located between the plates 23 23 and the ball-races 21 21 are stiff springs 24 24, the tendency of which is to force each wedge member toward the other, and thus raise the eccentrics 17 radially away from the shaft 14, the movement of the eccentrics being guided by the grooves 16 16, formed in the shaft. This serves to take up any wear and continually retains the eccentries in engagement with the piston.

Encircling the shaft 14 and eccentrics 17 17 is a rolling piston 25, tubular in conformation, against the perimeter of which the eccentrics 17 17 bear and operate to force the piston against and retain it in constant contact with the perimeter of the cylinder-band 4. The ecccntrics each carry a roller 26, which engages the piston and reduces the friction.

At either open end of the piston 25 is formed an offset or annular iiange 27 27, having a wedge-shaped groove formed therein for the reception of a plurality of packing-rings 28 28, each ring composed of arc-shaped sections angular in cross-section and having oppositely-beveled edges. These sections are ccnstantly forced out into contact with the heads 5 5 of the engine by means of springs seated at the base of the grooves, which springs may be secured to the sections of the innermost ring. The edges or ends of the tubular piston are beveled and form portions of the outer walls of the grooves.

Lubricant is supplied to the engines in any suitable manner, it being introduced into the abutment-chamber l0, from which it finds its way into the piston-chamber 8, and a branched pipe 31 is provided, the branches 32 32 of which collect the lubricant from the ypistonchamber and convey it to the main pipe 31, from which it flows into the interior of the piston and lubricates the shaft and its bearings.

The offset or abutment chamber 1() communicates with the piston-chamber 8 by means ofV a constricted passage 29, the chamber 10 being of a length corresponding to the length of the stroke of the abutment 30, which is received therein. This abutment consists of a solid plate provided with extensions 33 33 at its edges, the edges and the extensions received and operating in recesses 34 34, formed in the heads and extending nearly to the apertures 12 12, formed for the passage of the shaft 14. The extensions 33 33 completely fill the recesses 34 34 and lie iiush with the interior surface of the heads 5 5 and overlap the ends of the piston 25, thus aiding the packing-rings 28 28 in preventing the leakage of the motive power around the ends of the piston. The ends of an antifriction-roller 35 are journaled in the extensions 33, the roller bearing upon and snugly engaging the periphery of the piston at all times. The lower edge of the abutment 30 is composed of some antifriction bearing metal which engages the roller and prevents the leakage of motive power through the abutment.

The abutment fits smoothly in the constricted passage 29 and is adapted to have a reciprocatory motion, the opposite sides of the abutment engaging the walls of the constricted passage and are provided with oil-recesses 30' 30', which receive and carry the oil from the abutment-chamber.

The upper end of the abutment is provided j IOO IIO

similar plate '37, the wedge-shaped groove formed between these plates by reason of the inclination of their edges being filled with ani gularly-shaped sections38 38, of suitable antifrlction mater1al, the reception of which m the groove so formed creates a space between the two plates 36 and 37, which may be filled with soft packing, as shown. A removable and 37 and into the upper edge of the abutment 30. A suitable spring 40issecured by the bolt to the upper plate 37. The separation of theplates 36' 37 permits a slight movement thereof toward one another, which operates to force the packing material outward against the walls of chamber A 10, thus forming a snug joint. This result is aided bythe spring 40 and by the motive power, as will hereinafter be explained. The abutment is provided with apertures 30.30, which convey the lubricant from the abutment-chamber to the piston-chamber. 1.

Each motor when used separately may be provided with but .a ysingle inlet and a single outlet port; but in compounding theengines each is provided with two inlet-ports4l' 41j and two outlet-ports 42 42, the two inlet-ports being ofv course located on the opposite side of the piston from that occupied by thetwo outlet-ports.

A main pipe 43 conveys the motive power from any suitable source tothe motor. Whenv the latter are compounded, the main pipe is branched into pipes 44 44, which connect with theintlet-ports 41 41. Located in this branch pipe is a valve 45, by means of which the power is turned on or s hut off from the motor or motors.

Located near the motor in the main pipe is a governor-valve 46, operated by means of a wheel 47 on the main shaft 14, the wheel being connected with the governor-valve by means of a belt or chain 48, so that when the main shaft rotates vtoo rapidly the governorvalve will be operated to shut off a portion of or thelentire flow of motive power. A third or cut-off valve 49 is received and operates in a suitable chest, the valve being connected, by means of a rod 51, with an eccentric 50, keyed on the main shaft, the rotation of the shaft operating to cause the eccentric to alternately open and close the cut-off valve.l t

' A pipe 52 entends from the main motivepower-supply pipe 43 to theabutment-chamber 10, with which it communicates through the cap-plate 11. The purpose of this feedpipe is to convey a portion of the motive power into the abutment-chamber, where it operates to force the abutment against the periphery of the piston and yieldingly retain it in such position.

It will be observed that the abutmentchamber is enlarged aboveits constricted portion and that the abutment-plate is provided with what corresponds to a head or piston composed of the plates 36 and 37.

Now it is obvious that when the motive f power enters the piston-chamber through the inlet-port it will exert its energy against the abutment-plate to move the latter laterally. Naturally such an action would tend to cause j the abutment-plate to bind or wedge in its slideway. To avoid this objection, I have enlarged theVabutment-chamber and provided` the abutment with a head which affords more area for the motive power brought in by the feed-pipe 52 to operate against than is afj forded by that portion of the abutment exy' tended below the constricted portion and opj erated against by the motive power received into the ,piston-chamber.' The result kis thatl the' superiorpressure on the upper end of the abutment forcesthe latter downward in a direct line, overcoming/to, a great extent the lateral pressure on the lower portion of the C abutment. l bears against the rotary and revolving piston with considerable pressure during the first i half-revolutionof the latter. On the upward ior finishing stroke of the piston there is nol pressure on the upper end of the abutment, as l will be setforth hereinafter, and the pressure fexerted in they piston-chamber against the abutment-plate is much reduced owing to the expansion ofthe motive power.V y The downward pressure of the abutmentlplate alsov accelerates the movement of the piston or aids the power in the piston-chamber in rotating the piston, for the reason that .the lowerzendof the abutment contacts -with Ethe periphery of the piston behind or at one The lower end of the abutment IOO `side of the point of contact of the eccentrics 17 17 and the piston.,- The abutment therefore exercises a vdownward pressure upon the" piston during the first half of the stroke.

The abutment thus serves as an'indirect aux-,- riliaryin'combination with the motive power in the piston-chamber to propel the'piston.

'valve 53 is located at the intersection vof the branch pipes 44 44 to the inlet-ports 41 41 and. lthe main supply-pipe 43.

from the outlet-ports 42 42 and intersect with la second series of branch pipes 44 44, leading tothe inlet-ports of the second motor 2, a fourway Valve 55 being located at the intersection of said pipes.

motor 3 are merged into a single pipe 56, and at the merging-point a three-way valve 57 is vlocated. Links 58 are connected with the valves 53 5555 57, and a universal lever 59 is secured to the links, thus enabling the operator to shift .the entrance-port of the motive vpower from one side of the abutment to the other to reverse the direction of rotation of the shaft.

A valve 60 is located in the feeder-pipe 52 adjacent its point of entrance into the abut- Pipes 54 54 lead- The outlet-pipes fromthe last,Y

In compounding the motors a three-way;

IIO

Lil

ment-chamber 10, and an arm 61 is connected to this valve, whereby to alternately open and close the feeder-pipe.

In compounding the motors the feeder-pipe is extended over the entire series and communicates with the abutment-chamber of each motor. The pipe is also provided With a valve similar to that set forth located adjacent the point of entrance of the lfeeder to each of the abutment-chambers, the valves being provided with arms 61, which are each pivotally connected to a lever-rod 62. Pivotally supported at Aany suitable point is a bell-crank lever 63, one arm of which is secured to the lever-rod 62 and the opposite arm of which is connected to an eccentricrod 64. An eccentric 65, keyed on the shaft 14, is secured to the eccentric-rod, causing the reciprocation of the lever-rod 62 and the alternate partial rotation and reversal of the valves 60. In other words, the valves 60 60 are located at the j unctures of the pipe 52, with the short branch pipes leading into the abutment-chambers. These valves, which may be alternately three-way and four-way valves, are so located that the motive power in the pipe 52 is first admitted to the abutmentchamber in motor 1, but not to any of the others. These valves are so arranged that when the first valve 6() is turned to admit themotive power from the pipe 52 to the abutment-chamber of motor 1 that portion of the pipe 52 leading from the first to the second valve 60 is cut out of communication with the first valve 60. At that same time the second valve 60 (a four-way valve) is turned so that motive power can have access to the second abutment in motor 2; but since the first valve (a three-way valve) has closed the pipe 52, connecting` the first and second valves, no motive power passes to the second motor abutment-chamber. The third valve (a threeway valve) is turned similarly to the first valve. Now when the valves are reversed the first valve is rotated so that that portion of the branch pipe 52 from the main pipe 43 to the first valve 60 is cut out, and the motive power contained in the abutment-chamber of the lfirst motor is placed incommunication with that portion of pipe 52 leading from the first valve to the second valve. The motive power now has access to the abutment-chamber of the second motor, which chamber, in fact, is always in communication with the pipe 52; but the third valve 60, being a threeway valve, is turned in the same direction as is the first valve, thus closing communication between that portion of the pipe extending between the second and third valves and the abutment-chamber of the third motor. A reversal of the valves to their first position permits the exhaust from the abutment-chamber of the second motor to pass to the third motor, since the first and third valves are rotated in the same direction, the first valve permitting a fresh supply of motive power to enter through branch pipe 52 from' the main source to the abutment-chamer of motor 1. The feeder may finally communicate with the exhaust from the piston-chambenas shown.

The operation of the device will be understood from the foregoing in connection with the following: Steam is admitted through one or the other of the inlet-ports 41 41 to cause the rotation and revolution of the tubular piston 25, the motive power being cut off by valve 49 as soon as sufficient has entered to drive the piston. The cut-off valve can be regulated to cut off the motive power at any desired point in the stroke of the piston, whereby to permit a larger or smaller amount to pass into the motor. The motive power also passes through the feeder-pipe 52 and into the' abutment-chamber, the amount of power passing thereinto being governed by valves controlled by the eccentric 65'. The admittance of this motive power creates a direct and an indirect pressure upon the`piston25. In general the pressure admitted through valve 60 is cut offl when the shaft 14, and consequently the piston 25, has completed a quarter-rotation, while the pressure into the piston-chamber is discontinued or cut off by valve 49 when the piston has completed half `its rotation. `When the rolling piston has completed one hundred and seventy degrees o f its circular movement, the motive power passes out of one of the exhaust-ports 42 42v through pipes 54 and 44 to one of the inlet-ports 41 41 of motor No; 2,which is approximately one-third larger than motor No. 1 in order to obtain the same amount of power from the decreased motive power by providing a larger surface upon which to act. Thus the piston in the second engine is forcing the shaft 14 around, together with the piston in engine No. 1, which is now .at the highest point in its eccentric travel.

The pressure in the abutment-chamber of motorN-o. 1 ceases when the motor-piston has reached its lowest limit of travel, and the valve 6() is, operated so that the pressure will escape into the pipe 52 and thence into the abutmentchamber of motor No. 2 in order that there will be as little back pressure as possible on the piston in the first motor when it is on its upward travel.

It is evident that many changes might be made in the form and arrangement of the several parts described without departing from the spirit andv scope of my invention, and hence I do not Wish to limit myself to the exact construction herein set forth; but

What I claim as new, and desire to secure by Letters Patent, is-

1. In a motor, the combination with a shaft having transverse grooves formed therein, of

a piston, eccentric plates sliding] y received in the grooves on the shaft and means for con- IOO IIC

and a shaft having a portion of its surface Vformed into a seat, of aplate movably received in the seat on the shaft and a movable means supported upon the shaft and in eugagement with the plate to force the latter against the perimeter of the piston.

4. In a motor, the combination with a piston and a shaft having seats formed therein, of an eccentric slidingly received in the seat, an inclined memberlocated 'between the eccentric and the shaft, and means for operating the inclined member to force the eccentric against lthe piston.

5. In amotor, the combination with a shaft having a seat formed therein, of a piston encirclingthe shaft, an eccentric slidingly received in the seat and an inclined member located between the eccentric and the shaft, the inclined member -adapted to constantly retain the eccentric in frictional contact with the piston.

6. In a motor, the combination with a shaft having grooves formed therein, a portion of the shaft having a chorded seat formed thereon, and a piston encircling the shaft, of an eccentric having a recess formed therein, the shaft received in the recess, the walls of the recess slidingly received in the grooves, a wedge member movably supported on the chorded seat, the inclined face of the wedge member engaging the rear wall of the eccentric to force the periphery of the latter into engagement with the perimeter of the piston.

7. In a motor, the combination with a shaft and a piston, of an eccentric slidin'gly mounted on the shaft, an inclined member engaging the eccentric and means automatically bearing against the inclined member to cause the eccentric to constantly contact with the piston. 8. In a motor, the combination with a shaft and a piston, of an eccentric having a recess formed therein, the rear wall of the recess being inclined, a wedge-shaped member carried by the shaft, the eccentric adapted to embrace the wedge-shaped member and the shaft, and means for automatically actuating the wedgeshaped member to cause the abutment of the peripheries of the eccentric and the piston.

9. In a motor, the combination with a sh aft, and a piston, of a movable eccentric embracing the shaftymeans carried by the shaft and embraced by the eccentric for forcing the eccentric radially of the shaft and a spring member adapted to bear constantly against the means, the eccentric engaging the piston.

l 10. In a motor, the combination with a casing, a shaft, and a piston, of a ball-race supported on the shaft, balls in the ball-race engaging the casing, an eccentric slidingly mounted on the shaft, an inclined member carriedby the shaft and engaging the eccentric, and a spring member located on the shaft and bearing against the ball-race and the inclined member to force the eccentric against the piston.

11. The combination, in a motor, with a casing, a shaft and a piston connected with the shaft, of a ball-race secured on the shaft, and balls in the ball-race, the balls adapted to engage the casing to reduce friction and means for adjusting and retaining the ball-race in one position upon the shaft.

12. The combination, in a motor, with a casing, a shaft, of a tubular piston inclosing the shaft, the ends of the piston provided with annular grooved offsets stationarily secured thereto and depending into the bore of the piston, and expansible packing material located in the offsets and engaging the casing ofthe motor.

13. A motor comprising within a casing a piston, a shaft connected therewith and an abutment adapted to constantly contact with the piston, at its lower end, the upper end of the abutment received in an abutment-chamber, a plurality of plates carried by the upper end of the abutment, the plates spaced apart from one another and having cut-away portions, packing 'received in the cut-away portions, and means for removably and loosely securing the upper plates to the abutment 14:. In a motor, the combination with a shaft and a piston connected therewith, of an abutment-chamber, an abutment received in the abutment-chamber, the lower end of the abutmentadapted to maintain a constant contact with the piston, a plurality of cut-away plates secured to the upper end of the abutment, anguiar packing-sections received between the plates, and means for exerting pressure upon the uppermost plate whereby the packing is forced out against the sides of the abutmentchamber to form a tight joint.

15. In a motor,the combination with a shaft, and a piston connected therewith, of an abutment-cham ber, an abutment movably received therein, the lower end of the abutment adapted to maintain constant contact with the pis- IOO lIO

ton, packing-plates secured to the upper end of the abutment and a spring secured upon the uppermost packing-plate, the packingtact with the piston, the abutment provided with apertures for conducting lubricant from the abutment-chamber to the piston-chamber.

17. The combination in a motor-casing inclosing a piston chamber and an abutmentchamber offset from the piston-chamber and connected directly therewith, of a shaft, a piston connected thereto, an abutment received in the abutment-chamber, and engaging the piston, the piston-chamber-provided inlet and exhaust ports,and the abutment-chamber provided with a combined inlet and exhaust port.

18. The combination in a motor-casing provided withinlet and outlet ports, an abutmentchamber, a piston, a shaft actuated by the piston and an abutment received in the abutmentchamber, the chamber provided with a single port, pipe for conveying motive power to the vcasing and to the abutment-port and valve in the abutment-port adapted to change the latter from an inlet to an outlet port. v

19. The combination, in a motor with a piston-chamber, an abutment-chamber communieating therewith,a movable abutment received therein, a revoluble and rotatable piston against which the abutment bears and a shaft connected with the piston, of means for conveying motive power to the piston-chamber, a feeder for conveying motive power to the abutment chamber, a valve located in the feeder, an eccentric on the shaft, and means connecting the valve and eccentric whereby the motive power is cut olf from the abutment-chamber during the upward movement of the piston.

20. The combination in a motor, with a piston-chamber provided with inlet and outlet ports, a piston, a shaft driven thereby, and an abutment adapted to constantly engage the piston, of a main pipe for conveying motive power, branch pipes leading from the main pipe to the inlet-ports, a valve located in the main pipe for closing the pipe by hand, a governor valve located in the main pipe, means on the shaft for operating the governor-valve, a cut-off valve located in the main pipe, an eccentric on the shaft connected with the cut-off valve whereby to alternately close and open the cut-off valve, a valve located at the point of intersection of the main pipe with the branch pipes and means for operating the valve to direct the motive power into either of the inlet-ports.

2l. The combination with aplurality of motors gradually increasing in size from high to low pressure, each provided with aV plurality of inlet and outlet ports, a means for conveying motive power, branch pipes intersecting the conveying means and leading to the inletports of the first or high-pressure motor, a valve located at the intersection ofthe branch pipes with the conveying means, exhaustpipes leading from the outlet-ports of the motors and intersecting with the pipes leading to the inlet-ports of the remaining motors in the series, valves located at the intersection of the exhaust with the inlet-pipes, the exhaust-pipes of the last motor in the series merging into a single pipe, a valve located at the merging point, links connected with the valves and a universal lever to which the links are secured to permit the simultaneous operation of the valves when reversing the direction of rotation of the pistons in the m0- tors.

22. The combination with a plurality of motors of successively-increasing size, each motor provided with a piston, an abutmentchamber and an abutment adapted to engage the piston, of a main-line shaft with which each piston is connected, a source of motive power, a feeder for conveying a portion of the motive power into the abutment-chambers, valves located in the feeder and controlling the entrance-of the motive power into each of the abutment-chambers, an arm secured to each valve, a lever-rod to which each arm is secured, an eccentric on the shaft, and a pivotally-supported bell-crank lever to which the eccentric and the lever-rod are connected whereby to alternately open and close the valves simultaneously.

23. The combination with a motor-casing containing a piston-chamber, inlet and outlet ports therefor, and an abutment-chamber connected with the piston-chamber, a piston located in the piston-chamber and an abutment received in the abutment-chamber, of a source of motive power, the abutment-chamber provided With a single port, a feeder connecting the source of motive power and the abutmentport, connections independent of the feeder for conveying motive power to the inlet-ports of the piston-chamber, a valve -in the feeder, and means for automatically operating the valve to change the abutment-port alternately from an inlet to an outlet.

24. The combination with a plurality of connected motors of gradually-increasing size, each motor provided with inlet and outlet ports, a piston, an abutment-chamber and an abutment received therein and constantly abutting the piston, of a source of motive power, a universal feeder extending therefrom and connected with each abutment-chamber, a valve controlling the supply of motive power to` each abutment-chamber, a lever-rod connected with each valve, means for automatically operating the lever-rod to open or close the valves, the` exhaust from the first abutment-chamber passing throughv the universal feeder to the succeeding abutmentchamber of each motor in the series.

25. The combination with a motor comprising a casing provided with inlet and outlet ports, a shaft and a piston connected therewith, of an abutment-chamber, the lower end of the abutment engaging the piston, means for admitting motive power to the piston and to the abutment-chambers,v the abutment co- IOO IIO

operating to drive the piston and a valve for releasing the motive power from the abutment-chamber through its inlet-port when the abutment reaches the limit of its outward stroke.

26. The combination with a motor-casing containing communicating piston and abutment chambers, the piston-chamber provided with inlet and outlet ports, a piston and an abutment in their respective chambers, the lower ends of the abutment automatically and constantly engaging the periphery of the piston, the upper end of the abutment having a greater area than the area of one side of that portion of the abutment which extends into the piston-chamber and means for supplying the piston-chamber With motive power.

27. 1n amotor, the combination with a casing inclosing piston and abutment chambers, of a piston, a shaft Surrounded thereby, an

abutment, the floor of the abutment-chamber being inclined and a valved outlet connecting' with the lowest portion oi' the Hoor to educt foreign matter from the abutment-chamber.

Q8. In a motor, the combination with acasing inclosing piston and abutment chambers, of a tubular pistonin the piston-chamber and an abutment in the abutment-chamber, packing on the piston for preventing the passage of {iuids past the edges thereof, a lubricantsupply for the abutment and a eonveyer on the easing for conducting lubricant from the exterior to the interior of the piston.

ln testimony whereof I have signed this specification in the presence of two subscribing Witnesses.

HUGH T. DUNN. Witnesses:

CHARLES F. WADE, JOSEPH F. HARVEY. 

